I believe the answer is D. The milky way is a spiral galaxy, You can tell just by looking at it.
The answer is B. good luck :)
During freezing, energy is released by the mass of water without change in temperature. Such energy will also be required if the same mass of water has to be melted.
Then,
Number of moles = mass/molar mass = 253/18.02 =14.04 moles
Energy released = moles*molar enthalpy of fusion = 14.04*6.008 = 84.35 kJ
The correct answer is (A). The speed of light would increase to a speed larger than the maximum speed of light in vacuum.
The index of refraction is the ratio of speed of light in vacuum to the speed of light in a medium.
n=C/V
here, n is the index of refraction, c the speed of light in vacuum, v is speed of light in any medium.
Now if the value of index of refraction is less than one, than the value of speed of light would be greater than the speed of light in the vacuum.